7. PRSR 04-11-2007 - Laserfiche WebLink

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dominated by non-native plants. Soil erosion increased where native cover was removed, adding sediments to creeks, wetlands and lakes. Urbanization continues to fragment natural communities further with the addition of more roads, streets and utilities. Construction of all types altars and compacts soils, and changes the local hydrology. Large -areas of impervious surface and drainage of wetlands increases the amount of stormwater runoff and pollutants carried to local waters. . Non-native, aggressive species like European buckthorn have been added as landscape materials. Changes in habitat and the increasing presence of humans in the landscape has brought changes in animal populations, decreasing or eliminating some species like bluebirds and bison, and favoring others such as English sparrows and white-tail deer. Influence of Landform and Climate on Vegetation Types Plant communities that exist in any given area are the result of numerous biological and physical factors. These work in concert to influence plant communities in often subtle ways, and sometimes dramatic and immediate ways such as drought, or a tornado. Biological factors can include such varied things as the presence or absence of pollinators, burrowing activities, herbivory, or over utilization of an area by a single species or number of species. Of the physical factors, two have a consistently strong influence in the shaping of plant communities. These are climate and landform. The climate in east-central Minnesota is considered to be continental and subhumid, with long, cold winters and relatively brief, warm summers. Wide fluctuations in temperature and precipitation strongly influence the plant communities present in the region and causes plants to be adapted to extremes, rather than averages. Landforms also have a profound impact on the type of plant communities found in any area. As was mentioned previously, the landforms of the area are primarily glacial in origin. Direct glacial modification of the landscape, such as the deposition of till, and moraine, and the influence of periglacial processes such as outwash, have formed the vast majority of the landforms in this region. Most of the deposited materials associated directly with glaciers, such as till and moraine are unsorted. These consist of materials, which range in size from clay and fine sand to large boulders in a random arrangement. Overall, the materials deposited in the township tend to form well-drained to very well- drained landscapes with sands and gravels common. In addition to the influences of climate and landform, landscape position also has a profound impact on the type of plant communities supported. Angle, position, and aspect of slope all strongly influence plant species that can be supported in an area. Slope aspect plays a significant role since it can exaggerate the influence of the sun and the amount of water plants loose through their leaves on south- and southwest- Top of the World Park Addition Natural Area Management Plan 3